1. Field of the Invention
The present invention generally pertains to mineral mining processes and, more particularly, but not by way of limitation, to a mining system particularly adapted for the recovery of coal from coal seams.
2. History of the Related Art
The recovery of coal, ore, or other material from mineral bearing strata or seams has been the subject of technological development for centuries. Among the more conventional mining techniques, drum-type mining systems have found industry acceptance. Drum-type mining machines typically utilize a cutting head having a rotating cylinder or drum with a plurality of mechanical bits on an exterior surface for cutting into the mineral bearing material. The dislodged material is permitted to fall to the floor of the mining area, gathered up, and transported to the mining surface via conveyors or other transportation means.
Although drum-type mining machines have proven effective, conventional drum-type cutting systems generally rely solely on a mechanical cutting action which subjects motors and bits to considerable wear and produces significant amounts of dust. Also, to increase the productivity of conventional mechanical cutting machines will normally require the installation of larger and heavier cutting motors on the miner to produce the additional power needed.
Thus, there is a need for a reliable mining system which addresses the limitations of the above-described conventional mining systems and which achieves higher rates of penetration and improved productivity.
The present invention overcomes the foregoing and other problems with a water jet assisted, drum-type mining system which positions a plurality of high pressure water jets to cut the mining face independently of mechanical bits. This unique combination of mechanical and hydraulic cutting results in higher rates of penetration and improved productivity. The high pressure water used in cutting may be pumped via a hose line or other conduit from a remote location. Alternatively, a high pressure water pump may be located on the chassis of the miner. Of course, this means that the cutting motors on the drum-type miner itself can be much smaller than the motors used to generate equivalent production by conventional means. Moreover, because the mining face is pre-scored by the water jets, the amount of wear on both the mechanical bits and the motors may be significantly reduced.